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Randomized Study of Collagen Cross-Linking With Conventional Versus Accelerated UVA Irradiation Using Riboflavin With Hydroxypropyl Methylcellulose

Two-Year Results

Hagem, Anne Marie, MD*,†; Thorsrud, Andreas, MD*,†; Sandvik, Gunhild Falleth, MPhil*,†; Drolsum, Liv, MD, PhD*,†

doi: 10.1097/ICO.0000000000001791
Clinical Science

Purpose: To compare the clinical outcome 2 years after corneal collagen cross-linking (CXL) with conventional and accelerated ultraviolet A (UVA) irradiation using riboflavin with hydroxypropyl methylcellulose.

Methods: Prospective randomized controlled study. Forty patients with keratoconus (40 eyes) were randomized to either CXL using conventional 3 mW/cm2 UVA irradiation for 30 minutes (CXL30 group) or accelerated 9 mW/cm2 UVA irradiation for 10 minutes (CXL10 group). In both groups, a solution of 0.1% riboflavin with 1.1% hydroxypropyl methylcellulose (methylcellulose–riboflavin) was used. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), and Scheimpflug tomography were performed at baseline and after 24 months.

Results: Both groups had statistically significant improvement in CDVA and maximum keratometric reading compared with baseline; however, with no statistically significant difference in the change between the 2 groups. No significant changes in flattest, steepest and mean keratometry (K1, K2 and K mean) were found in either of the groups. There were no statistically significant changes in ECD in either group after 2 years or in the difference in the change between the 2 groups. A literature review showed comparative clinical outcome after accelerated CXL compared with conventional CXL; however, in several studies, there was a tendency for less pronounced corneal flattening after accelerated CXL.

Conclusions: Improvement in visual acuity and maximum keratometric reading 2 years after CXL was found after both conventional and accelerated UVA irradiation using methylcellulose–riboflavin. This suggests that when using riboflavin with methylcellulose, the less time-consuming accelerated protocol is a valuable and effective option in CXL treatment.

*Department of Ophthalmology, Oslo University Hospital, Norway; and

Centre for Eye Research, University of Oslo, Norway.

Correspondence: Anne Marie Hagem, MD, Department of Ophthalmology, Oslo University Hospital HF Ullevål, Postboks 4950 Nydalen, 0424 Oslo, Norway (e-mail:

The authors have no funding or conflicts of interest to disclose.

Received June 20, 2018

Accepted September 07, 2018

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